1. Technical Field
The present invention generally relates to monitoring devices used to monitor at least one engineering condition of a pneumatic tire and, more particularly, to a monitoring device and patch combination where the antenna of the monitoring device is disposed in the patch. Specifically, the present invention relates to an encapsulated monitoring device and a patch for attaching the encapsulated monitoring device to the innerliner of a pneumatic tire with the antenna of the monitoring device being disposed in the patch and including a connector that allows the user to selectively connect the antenna to the monitoring device.
2. Background Information
It is often desired in the art to monitor an engineering condition of a tire while the tire is installed and in use on a vehicle. Typical desirable measurements are the number of tire rotations, the internal temperature of the tire, and the internal pressure of the tire. These measurements are preferably taken while the tire is in use on the vehicle without having to remove the tire from the vehicle or specifically position the tire to take the measurement.
Numerous types of monitoring devices are known in the art to perform these measurements. One type of monitoring device uses a passive integrated circuit embedded within the body of the tire that is activated by a radio frequency transmission that energizes the circuit by inductive magnetic coupling. Other prior art devices used for monitoring tire conditions include self-powered circuits that are positioned external of the tire, such as at the valve stem. Other active self-powered programmable electronic devices are disclosed in U.S. Pat. Nos. 5,573,610, 5,562,787, and 5,573,611 which are assigned to the assignee of the present application.
Each of the active self-powered programmable electronic devices includes an antenna that is used to transmit the information gathered by the monitoring device to an information gathering device positioned outside of the tire. One of the problems in the art is to position the antenna such that the information gathered by the monitoring device is accurately transmitted to the information gathering device outside of the tire. It is desired to position the antenna against the sidewall of the pneumatic tire so that the transmission waves pass directly into the sidewall. In the past, the antenna of the monitoring device generally extended into the interior chamber of the tire such that the transmission waves had to pass first through the air inside the tire, through the innerliner, through the tire sidewall, and then through the air to the information gathering device. It is desired in the art to provide an antenna for an active, self-powered programmable electronic device that is positioned so that the transmission waves do not have to first pass through the inner chamber of the tire before entering the tire sidewall.
The bead ring and apex filler of the tire tend to interfere with the transmission from the monitoring device. It is thus desired in the art to position the antenna away from the bead ring and apex filler so that the transmission through the tire sidewall is as strong as possible. On the other hand, it is also desirable to position the monitoring device as close to the bead ring as possible because that area of the tire sidewall is a low flex area that stretches less than the middle portion of the tire sidewall. It is thus desired in the art to provide a method for attaching an antenna and a monitoring device that accommodates the desired position for both elements.
The monitoring devices known in the art are typically encapsulated with an encapsulation material that provides structural support to the monitoring device so that the device is not destroyed by the forces normally encountered and experienced by a pneumatic tire. In some situations, the process of encapsulation must take into account that the antenna must extend from the encapsulated monitoring device. It is desired to provide a monitoring device configuration that eliminates this encapsulation problem by positioning the antenna apart from the monitoring device.
One method of connecting the monitoring device to the innerliner of a tire includes the use of a rubber attachment patch to carry the monitoring device with the inner surface of the rubber attachment patch being configured to securely adhere to the innerliner of a tire. It is desired that the sensitive electronic monitoring device and the rubber patch be capable of being manufactured in separate locations and assembled when the monitoring device is attached to the innerliner of a tire. Separating the rubber attachment patch and the sensitive monitoring device also allows the rubber attachment patch to be aggressively attached to the innerliner of a tire without the risk of damaging the sensitive monitoring device. After the rubber attachment patch is securely anchored to the innerliner, the monitoring device may be attached to the patch.
In view of the foregoing, it is an objective of the present invention to provide a monitoring device and patch combination that may be fabricated at separate manufacturing facilities and then connected together when the monitoring device is installed in a pneumatic tire.
Another objective of the present invention is to provide a monitoring device and patch combination wherein the antenna for the monitoring device is carried by the patch.
A further objective of the present invention is to provide a monitoring device and patch combination that positions the antenna in a manner that causes the transmission waves to pass directly into the tire sidewall away from the bead ring and apex filler of the tire.
Another objective of the present invention is to provide a monitoring device and patch combination that allows the antenna to be ideally positioned away from the bead ring while allowing the monitoring device to be positioned closer to the bead ring.
Another objective of the present invention is to provide a monitoring device and patch combination that has a connector that allows the user to form the connection between the antenna and the monitoring device after the individual elements have been fabricated.
A further objective of the present invention is to provide a monitoring device and patch combination that automatically forms the connection between the antenna and the monitoring device when the monitoring device is aligned and connected with the patch.
Another objective of the present invention is to provide a method for installing a monitoring device on the innerliner of a tire that allows the patch of the combination to be connected prior to the monitoring device and aggressively stitched to the innerliner without the danger of damaging the monitoring device.
Another objective of the present invention is to provide a monitoring device and patch combination that automatically forms the connection between an antenna embedded within an anchoring patch adhered to the innerliner of a tire when the monitoring device and patch combination is adhered to the anchoring patch.
Another objective of the present invention is to provide a method and combination that are of simple construction, that achieve the stated objectives in a simple, effective, and inexpensive manner, that solve the problems, and that satisfy the needs existing in the art.
These and other objectives and advantages of the present invention are obtained by a monitoring device and patch combination used to monitor the conditions of a pneumatic tire having an innerliner, the combination including a monitoring device; a patch selectively carrying the monitoring device, the patch adapted to mount the monitoring device on the innerliner of the pneumatic tire; an antenna carried by the patch; and a connector selectively physically electrically connecting the antenna to the monitoring device.
Other objectives and advantages of the invention are obtained by a method of installing a monitoring device on the innerliner of a tire including the steps of providing a monitoring device having a first connection element; providing a patch separate from the monitoring device, the patch having an antenna connected to a second connection element; attaching the monitoring device to the patch; and connecting the first and second connection elements to create a connection between the antenna and the monitoring device; and mounting the patch on the innerliner.